Apparatus for firing a plurality of fastening tools



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INVENTOR July 19, 1966 o. P. STERNER APPARATUS FOR FIRING A PLURALITY OFFASTENING TOOLS Filed Oct. 7, 1964 ATTORNEYS,

July 19, 1966 o. P. STERNER 3,261,527

APPARATUS FOR FIRING A PLURALITY OF FASTENING TOOLS Filed Oct. 7, 1964 3Sheets-Sheet 2 CZW IN VENTOR.

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July 19, 1966 o. P. STERNER 3,261,527

APPARATUS FOR FIRING A PLURALITY OF FASTENING TOOLS Filed Oct. '7, 19645 Sheets$heet 5 INVENTOR.

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United States Patent 3,261,527 APPARATUS FOR FIRING A PLURALITY 0FFASTENING TOOLS Olle P. Sterner, Park Ridge, 111., assignor to SignodeCorporation, a corporation of Delaware Filed Oct. 7, 1964, Ser. No.402,284 9 Claims. (Cl. 227-7) This invention relates to an apparatus forfiring a battery of power operated guns of the type adapted to drivestaples, nails, or other fasteners into a workpiece and, particularly,with means for controlling the operation of the tool control mechanismsto insure proper firing of each gun.

it has been the practice with some fastening tools to actuate the toolsby some device motivated by the engagement of some part of the gun, withthe workpiece into which the fastener is to be driven. If the surface ofthe workpiece is not level, and it is desired to fire a plurality offasteners with the use of a plurality of guns, it is necessary to makesuitable provisions to insure that the individual guns will not fireuntil they are in actual contact with the workpiece. If this is not doneand all the guns are fired simultaneously, some of the fasteners may notbe driven the correct amount. Furthermore, if the guns are mounted on abeam that is moved to carry the guns into engagement with one surface ofthe workpiece, some of the guns may not be fired before the beam startson its movement away from the workpiece.

In order to compensate for irregularities in the surface of theworkpiece, attempts have been made to hold the guns in place by springsor by gravity in such a way that the guns may be lifted from thesupporting beam in areas where high points occur in the surface intowhich the fasteners are to be driven. It has been found, however, thatwhen a gun mounted in this manner is fired, the recoil sometimes bouncesthe gun off the workpiece, and, when the gun drops back to theworkpiece, the trigger may be actuated to fire the gun a second time anddrive a second fastener into the workpiece.

The present invention will be described in connection with .a battery ofpower ope-rated guns, which while operated by compressed air may beoperated by electric power, inertia devices, or any other suitablemedium.

Furthermore, the invention is intended for use wit-h power operatednailing or stapling guns, but its advantage may be utilized inconnection with other similar evices. The details of the gun employed donot constitute any part of the invention and therefore will not bedescribed.

In accordance with the present invention, a group of guns are supportedby a beam or other support member that may be moved vertically orpivotally toward and from a workpiece into which fasteners are to bedriven. As the beam is moved toward the workpiece, the guns are moved inthe same direction. Each gun stops moving when it engages a surface ofthe workpiece, but the beam continues to move in the same directionuntil each gun is in engagement with the workpiece.

A trigger actuating lever is pivotally mounted on each gun and iscontrolled by the movement of the main support assembly. As each gunengages the workpiece, its respective lever is subjected to springpressure until sufiicient pressure is built up to move the lever andthereby actuate its associated trigger. A-ny recoil from the firing ofthe gun compresses the spring that actuates the lever, thus preventing asecond firing. After the guns are fired, the beam member returns theguns to their initial position.

The structure by means of which the above mentioned and other advantagesof the invention are attained will be fully described in the followingspecification, taken in "ice conjunction with the accompanying drawingsshowing two preferred illustrative embodiments of the invention, inwhich:

FIGURE 1 is an end elevational view of the apparatus incorporating thepresent invention;

FIGURE 2 is a rear elevational view of the apparatus of FIGURE 1;

FIGURE 3 is an enlarged fragmentary rear elevational view of the gangmounting and parts of the trigger actuating mechanism;

FIGURE 4 is an enlarged view, partly in section and partly in elevation,showing the trigger actuating mechanism;

FIGURE 5 is a side elevational view of an apparatus illustrating anotherembodiment of the invention;

FIGURE 6 is an enlarged side elevational view of the structure of FIGURE5, with parts removed to facilitate illustration of the triggeractuating mechanism; and

FIGURE 7 is an enlarged view, partly in section and partly in elevation,of the structure shown in the central portion of FIGURE 6.

In FIGURES 1 and 2 of the drawings, there is shown a frame 11 comprisinga pair of spaced uprights 12, a pair of transverse angle irons 13, and aplurality of braces 14. Each upright 12 comprises a pair of verticallydisposed angle irons 15 having their lower ends secured in spacedrelationship to a bracket 16 bolted to the floor. The purpose of the gapor slot 17 between angle irons 15 will be described later. Eachtransverse member 13 is secured at its ends to one edge of uprights 12intermediate the height of the vertical uprights. Each brace has one endsecured to an upright 12 and to a transverse angle iron 13. The bracesextend diagonally between the uprights 12 and the transverse angleirons. A pair of channel irons 18, secured to angle irons 13 in spacedrelationship adjacent each upright, extend at right angles to angleirons 13. A roller 19 is rotatably mounted in each pair of channelirons. Each roller 19 is one of a series of parallel rollers (not shown)that cooperate to form a conveyor upon which a workpiece 20 is supportedas it is moved under a group of transversely aligned vertically disposedguns 21. An endless belt of a width sufiicient to cover the transverselyspaced rollers 19 may extend around all of said rollers, if desired. Anadjustable center support 22 secured to one of the angles irons may beprovided adjacent the bottom of the workpiece to keep it from sagging.

As shown in FIGURES 3 and 4, a flat plate 23 is rigidly secured to thetop of each gun 21 by a plurality of bolts 24. Sleeves 25 mounted oneach bolt and fitting into recesses 26 in the top of each gun space theplate 23 above the top of the gun. One edge of the plate 23 extendslaterally beyond the edge of the gun and is provided with an aperture 27through which a vertical pin 28 extends. The lower end of the pin 28extends through an aperture 29 in the horizontal arm 30 of a bracket 31secured to the lower portion of the gun and extending laterallytherefrom. The pin 28 is slidable vertically relative to the plate 23and the bracket 31 for reasons hereinafter disclosed.

Two plates 32 at opposite edges of the frame are each mounted in a slot17 in one of the uprights 12 so that they may be moved vertically ortransversely relative to the frame. Two hydraulic cylinders 33 aremounted on the uprights at opposite edges of the frame and each cylinderhas a piston rod 34 connected to one plate 32 to move said platesvertically. The plates 32 are secured to opposite ends of a beam 3-5extending transversely of the frame. An angle iron 36 extends betweenthe plates 32 and is secured to the lower portion of each of saidplates. One leg 37 of the angle iron 36 is provided with r 3 an aperture38 through which the lower end of the pin 28 extends.

The leg 3-7 is positioned below the horizontal arm 3 of the bracket 31and normally supports the weight of the guns 21. Each gun movesdownwardly by gravity but is restrained by the engagement of the armwith the leg 37 of angle iron 36. When the beam 35 is raised, the leg 37engages the arm 30 to raise the gun from which said arm 30 extends. Thestructure of the gun support assembly is reinforced by diagonal braces39 and vertical braces 40.

A hydraulic cylinder 41 is secured to one of the uprights and has apiston rod 42 connected to a lug 43- welded to the beam 35 so that itcan move the gun assembly transversely of the frame. The hydrauliccylinders 33 are both actuated every time a row of fasteners is to bedriven, but the hydraulic cylinder 41 is actuated only at the start ofan operation to position the gun assembly laterally wit-h respect to theworkpieces into which the fasteners are to be driven.

A flat plate 44 is welded to the top surface of the beam 35 and extendsforwardly of said beam. The portion of plate 44 extending forwardly ofthe beam is provided with a plurality of apertures .45 through each ofwhich the upper end of a pin 28 projects. The interengagement of eachpin 28 with a pair of aligned apertures 45 and 3 8 enables each pin 28to guide the guns during their vertical movement as the beam 35 is movedvertically by the hydraulic cylinders 33. A pin 46 extends transverselythrough each pin 28 so as to project on both sides thereof. The pins 46are positioned above the plate 44 and are engaged by said plate as theplate is moved upwardly. The interengagement of the plate 44 with pins46 moves each pin 28 upwardly as the plate 44 is moved upwardly.

A bar 47 is pivotally mounted on a bolt 48 located between every pair ofpins 28. Each bar 47 is spaced above the plate 35 by a plurality ofcollars 49 encircling the bolt 48 between the plate 44 and the bar 47.The bolt 48 extends through aligned apertures 50 and 51 in bar 47 andplate 44, respectively, and is held in place by an enlarged head 52 anda nut 63. Each bar 47 engages the tops of two pins 28 to move themdownwardly when the plate 44 is moved downwardly.

One end of each bar 47 has a fixed pin 54 depending therefrom to engageone side of the pin 28, and a spring pressed pin 55 normally urgeddownwardly by its spring 56 to engage the pin 28 at a diametricallyopposite point. The pins 54 and 55 are located on opposite sides of pin28 so that the bar 47 cannot be moved pivotally when the pin 55 is inits down position. If any gun 21 is to be removed from the assembly, itis necessary to remove the pin 28 that extends through the plate 23 andbracket 31 secured to said gun. The pin 55 is moved upward against theaction of its spring, and the bar 47 is moved pivotally out ofengagement with both pins 28. Either pin 28 may then be pulled upwardlyto release its adjacent gun 21.

A rod 57 having an enlarged end 58 extends downwardly through anaperture 59- in the plate 44 adjacent every gun. The lower end of therod 57 extends through an aperture in one end of a lever 60 pivotedintermediate its length to the gun 21, as indicated at 61. The other endof the lever 60 is positioned below a button or trigger 62 dependingfrom the handle 63 of the gun 21. When the trigger 62 is pressedinwardly toward the handle of the gun, the gun is actuated to drive afastener into the workpiece supported on the conveyor under the gun 21.

A compression spring 64, coiled around rod 57, has one end bearingagain-st the underside of the plate 44 and its other end bearing againsta nut 65 fixed to the rod 57 adjacent its lower end but spaced above thelever 60. When the beam 35 is moved downwardly, the plate 44 compressesthe spring 64, but, as long as the gun is moving downwardly with thebeam 35, the spaced relationship between the nut 65 and the lever 60remains fixed. As soon as the bottom of the gun projection 66, throughwhich the fastener is discharged, engages the workpiece 20, the downwardmovement of the gun stops, while the beam 35 and plate 44 continue theirdownward movement. The stroke of cylinders 33, which controls thedownward movement of the beam 35, is long enough to cause every gun toengage the workpiece before the downward stroke of cylinders 33 iscompleted;

Continued downward movement of the beam 35 after the projection 66 is inengagement with the workpiece causes the plate 44 to compress the spring64 to move the nut 65 into engagement with the lever 68. The verticalposition of the pivot 61 is fixed at the time the downward movement ofthe gun is stopped. As the compression of V the spring 64 is increasedby the downward movement of plate 44, pressure of the nut 65 against thelever 60 is increased until it forces the lever to move about its pivot61. The pivotal movement of the lever 60 presses the trigger 62 upwardlyto fire the gun and thereby drive the fastener into the workpiece.

It will be noted that the gun is not fired until sometime after itsdischarge member is in engagement with the workpiece, thereby making itimpossible for the gun to fire prematurely. G uns that are fired bycontact with the workpiece may fire prematurely if the workpiece is notlevel. and one part of the discharge member hits a high spot on thesurface of the workpiece. Each gun is fired individually, but all ofthem are fired before the guns start moving upwardly with the upwardstroke of the piston rod 34. Often, when a gun is fired, the recoil ofthe firing mechanism causes the gun to jump away from the workpiece. Ifthe firing mechanism is actuated by contact with the workpiece, it maybe actuated a second time when the gun moves back to the workpiece afterthe force of the recoil moves it away.

An accidental second firing of the gun, such as described above, is notpossible with the trigger actuating mechanism of the present invention.As shown best in FIGURE 4, the lever 60, which moves pivotally to pressthe trigger 62 upwardly to actuate the firing mechanism, is movedpivotally in the required direction by the downwardly exerted force ofthe spring 64. The downward pressure of the spring 64 will hold thelever 60 with its shorter end pressed upwardly in contact with thetrigger 62 until the cylinders 3-3 start their upward stroke and thusrelease the spring 64 from compression. If the recoil of the firingmechanism makes the gun bounce upwardly from the workpiece, the lever 60Will move upwardly with the gun, and will retain the spring 64 undercompression, thus preventing a second firing.

In FIGURES 5 and 6, there is shown another embodiment of the inventionin which a group of power operated guns 67 mounted between a pair ofuprights 105 (only one of which is shown) are pivotally moved about ashaft 68 to bring each of them into engagement with a workpiece 69 intowhich fasteners. are to be driven at an angle. In this embodiment, theworkpiece is placed on a stationary table 70 or other suitable surface,and is positioned relative to the gun by a guide 71 having a screwadjustment mechanism 72.. A vertical adjusting screw mechanism 73regulates the vertical position of a support bar 74 having an aircylinder 75 secured to its outer end, as indicated at 76.

A piston rod 77 projecting from one end of the cylinder 75 is pivotallyconnected, as indicated at 78, to one end of an arm 79. The arm 79 iskeyed to the shaft 68, as indicated at 80. Accordingly, the piston rodrotates the shaft 68 in clockwise direction, as viewed in FIGURES 5 and6, during its outward stroke, and in counterclockwise direction duringits inw ard stroke.

An arm 81, having a hook 82 at one end fitting over shaft 68, is rigidlyfixed to a flat plate 83 by screws 84. The gun 67 is secured to theplate. 83 by screws 85. A block 86, keyed to the shaft 68 at 87, has aplate 85 welded to one surface thereof. The block 86 and plate 88 movepivotally with the shaft 68 as the shaft is rotated is moved toward theleft.

in either direction by the piston rod 77. A rod 89 is pivotally securedat one end to the plate 88, as indicated at 90. The inner section 91 ofthe rod, adjacent pivot 90, is smaller in diameter than the outersection 92. A washer 93 is impaled on section 91 of the rod and isadapted to butt against the shoulder at the inner end of section 92.

A strip 94, fixed to one side of the plate 83 by the screws 84 has arecess 95 in one surface thereof. The section 91 of the rod extendsthrough the recess 95, through an aperture 96 in the bottom of therecess, and through an aperture 97 in one end of a lever 98 that ispivotally secured to the plate 83, as indicated at 99. The other end ofthe lever 98 is engageable with a button or trigger 100 adapted toactuate the firing mechanism of the gun. A compression spring 101encircles section 91 of rod 89 between the lever 98 and the washer 93.Another compression spring 102, large enough to fit over the washer 93,encircles section 92. One end of the spring 102 is seated in the recess95 and is biased against the bottom of said recess. The outer end of thespring 102 is biased against an annular collar 103 secured to section 92at its outer end in any suitable manner.

As the piston rod 77 moves outwardly of its cylinder 75, it moves arm 79to rotate shaft 68, thus moving plate 88 around shaft 68 as a pivot. Asviewed in FIGURE 6, this movement is toward the left, thereby tending tocompress the springs 101 and 102. The spring 101 is shorter than thedistance between the washer 93 and the lever 98. Therefore the washer 93must move toward the lever before the spring 101 can be compressed. Thespring 102, however, extends from the collar 103 to the bottom of therecess 95 and is compressed as soon as the rod 89 The compression ofspring 102 moves the gun pivotally to the left until the nose of the gunengages the workpiece.

The pivotal movement of the gun to the left is stopped by the engagementof the nose 104 with the workpiece, but, as in the embodiment of FIGURES1 to 4, the gun is not fired by the engagement with the workpiece, andthe piston rod 77 continues its outward stroke. The continued rotationof the shaft 68 moves the rod 89 to the left, and, since the spring 102cannot move the strip 94 to the left, the washer 93 is moved into therecess 95 and compresses the spring 101. The spring 101 is sodimensioned that it exerts sufficient pressure against the adjacent endof lever 98 to move it about its pivot 99 to actuate the trigger 100 andfire the gun before the piston completes its outward stroke. Asdescribed above in connection with the embodiment of FIGURES 1 to 4, thedelay in firing the guns 67 until the spring 101 builds up pressureagainst the lever 98 prevents premature firing of the gun, and thespring arrangement prevents accidental second firing if the gun fallsback into engagement with the workpiece after being forced away from itby the recoil force of the first firing.

After all of the guns 67 are fired, the piston rod 77 completes itsoutward stroke and starts moving inwardly relative to its cylinder 75.The inwlard movement of the piston rod reverses the direction ofrotation of the shaft 68 and moves the plate 88 pivotally toward theright, as viewed in FIGURE 6. A block 108, fixed to one edge of plate88, has a stud 109 projecting therefrom. As the plate 88 moves to theright, the stud 109 engages the rear surface of the strip 94 to move thegun 67 pivotally to the right to return it to its initial position.

Although I have described two preferred embodiments of the invention inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, rather than restrictive, as many detailsof structure may be modified or changed without departing from thespirit or scope of the invention. Accordingly, I do not desire to berestricted to the exact structure described.

I claim:

1. An apparatus for controlling the firing of a plurality of fasteningguns including a support member supporting said guns in spacedrelationship to a workpiece, means for moving said support member toposition said :guns in engagement with the workpiece, means to operatesaid guns and lost motion means held by said support member and beingoperable after said guns are in engagement with said workpiece toactuate said gun operating means.

2. An apparatus for controlling the firing of a plurality of fasteningguns including a support member adapted to support the guns in spacedrelationship to a workpiece, a plate fixed to said support member andprojecting therefrom, means for moving said support member to positionsaid guns against a workpiece, a trigger control for each of said guns,a lever pivoted intermediate its ends to each of said guns with one endof each lever disposed adjacent a trigger, a spring confined between theopp'oiste end of each of said levers and said plate, each of saidsprings being moved into engagement with said opposite end of itsrespective lever and pressed thereagainst by movement of said supportmember to pivot said lever to press a trigger and fire a gun, and lostmotion means preventing movement of said springs into engagement withits lever until after its associated gun is in engagement with saidwork-piece.

3. An apparatus for controlling the firing of a plurality of fasteningguns each having a trigger, a lever pivotally secured intermediate itsends to each of said guns with one end adjacent a trigger, a compressionspring engageable with the opposite end of said lever, means engageablewith said spring to compress it against said lever, whereby said leveris pivoted to operate said trigger, and means for supporting and movingeach of said guns into engagement with a workpiece and to move saidfirst mentioned means into compressing engagement with said spring afterthe gun engages the workpiece, whereby the guns will be in positiveengagement with the workpiece before they are fired.

4. An apparatus for controlling the firing of a battery of fasteningtools including a support member for sup porting said tools, a triggerprojecting from each of said tools for effecting firing of same, each ofsaid tools having a lever engageable with the trigger of said tool, andlost motion means between said support member and lever whereby each ofsaid tools will be moved into on gagement with a workpiece prior to theengagement of its lever with its trigger.

5. An apparatus for controlling the firing of a battery of fasteningguns including a support member for supporting said guns in spacedrelationship to a workpiece, a trigger projecting from each of saidguns, a lever pivotally secured intermediate its ends to each of saidguns with one end thereof positioned to engage a trigger, a compressionspring adapted to engage the opposite end of each of said levers, meansprojecting from said support member in alignment wt'ih each of saidsprings and movable into engagement therewith to compress it against theadjacent end of one of said levers to pivot same and bias its respectivetrigger into gun actuating position, means to move in sequence each ofsaid guns into engagement with said workpiece and said first mentionedmeans into engagement with each of said springs to insure engagement ofa gun with said workpiece prior to the gun being fired.

6. An apparatus for controlling the firing of a battery of fasteningguns including a support member for pivotally supporting said guns inarcuately spaced relationship to a workpiece, means for pivotally movingsaid support member to position said guns in engagement with aworkpiece, means to operate said guns, and lost motion means to insureengagement of each gun with said workpiece prior to actuation of saidgun operating means.

7. An apparatus for controlling the firing of a battery of fasteningguns including a pair of spaced uprights, a shaft rotatably mounted insaid uprights for pivotally supporting said guns in arcuately spacedrelationship to a workpiece, separate means for firing each of saidguns,

means for rotating said shaft, two springs actuated sequentially byrotation of said shaft to pivotally move each of said guns intoengagement with said workpiece and to actuate said separate means withrespect to any one of said guns after it is moved into engagement withsaid workpiece.

8. An apparatus for controlling the firing of a battery of fasteningguns comprising a rotatable shaft for pivotally supporting said guns inspaced relationship to a workpiece, a plate rigidly secured to each ofsaid guns and projecting therefrom, means to rotate said shaft, a rodoperatively connected to said shaft, rotational movement of said shaftbeing effective to move said rod axially, a compression spring engagingsaid rod and said plate, said rod compressing said spring as it is movedaxially to position said gun in engagement with said workpiece, atrigger for actuating said gun, a lever engageable with said trigger,and a second compression spring engaging said rod, said rod compressingsaid second spring as said rod is moved axially after said gun is inengagement with said workpiece to move the lever to actuate the trigger.

9. An apparatus for controlling the firing of a battery of fasteningguns including a support member for supporting said guns in spacedrelationship to a workpiece,

a plate fixed to said support member and projecting therefrom, means formoving said support member to position said guns in engagement with saidworkpiece, a trigger projecting from each of said guns, a lever pivotedintermediate its length to each of said guns with one end adjacent oneof said triggers, spring means confined between the opposite end of eachlever and said plate, each of said spring means being positioned to bepressed against the opposite end of one of said levers by movement ofsaid support member after said gun is in engagement with said workpieceto pivot said one lever to move the adjacent trigger into gun actuatingposition, each of said spring means being pressed against said plate byits related lever upon application of any recoil force of suflicientstrength to move the related gun away from said workpiece to preventsecond firing of said gun upon its return to said workpiece after anyrecoil.

References Cited by the Examiner UNITED STATES PATENTS 2,743,442 5/1956Davies 227156 X 2,755,470 7/1956 Johnson 227l52 X 2,897,503 8/1959Schafroth 227130 X GRANVILLE Y. CUSTER, IR., Primary Examiner.

1. AN APPARATUS FOR CONTROLLING THE FIRING OF A PLURALITY OF FASTENINGGUNS INCLUDING A SUPPORT MEMBER SUPPORTING SAID GUNS IN SPACEDRELATIONSHIP TO A WORKPIECE, MEANS FOR REMOVING SAID SUPPORT MEMBER TOPOSITION SAID GUNS IN ENGAGEMENT WITH WORKPIECE, MEANS TO OPERATE SAIDGUNS AND LOST MOTION MEANS HELD BY SAID SUPPORT MEMBER AND BEINGOPERABLE AFTER SAID GUNS ARE ENGAGEMENT WITH SAID WORKPIECE TO ACTUATESAID GUN OPERATING MEANS.